“I was so bad with the food and alcohol in Nashville,” the actress confesses in the May issue of Harper’s Bazaar. “If you saw me naked compared to what I looked like when I did Iron Man 2, where I was eating so well and exercising every day . . . I’ll get it back together, but I just have never eaten so much fried food and white flour in my life, ever.”

In the upcoming film -- which wrapped up shooting in Nashville last month -- Paltrow plays troubled country star Kelly Canter. Tim McGraw plays her husband and manager.

In the Harper's cover story, Paltrow has more to say about her real-life husband, Coldplay frontman Chris Martin, whom she calls “deeply lovely and special.”

“He loves the fact that I’m working and was so fulfilled by this job that I did in Nashville. He’s my biggest supporter.”

The May issue of Harper’s Bazaar hits newsstands on April 27. You can read the full cover story on Paltrow here.